Waterproof metallic explosive.



STATES PATENT OFFIOR.

THOMAS AB AHAM BAYLiss, 0F KINGS NORTON, NEAR BIRMINGHAM, AND

HENRY WI DER BROWNsDoN, OF LONDON, ENGLAND.

W TER ROOF METALLIC :xPLoswE.

Specification of Letters Patent.

Patented Feb. 26,4907.

implication filed Angus 14, 1905. Serial No. 274.185.

To all whom it may concern:

Be it known that we, THOMAS ABRAHAM BAYLIss and HENRY WINDER BRowNsDoN, subjects of the King of Great Britain, residing at Kings Norton, near Birmingham, England, and No. 19 Wellington road,Oharlton,

'London, S. E., England, respectively, have invented certain new and useful Improvements in Waterproof Metallic Explosives, of which the followingis. a specification.

, The said invention consists of the im-' provements in r addltions hereinafter described to the materials employed in the manufacture of percussion-caps, detonators, igniters, fuses, and other primers used in firearms and munitions of war for the ignition or detonation of explosives, the said improvements or additions having for their-principal sion-caps or detonators containing fulminate or other sensitive compositions the compo sition of the cap or detonator after being pressed is varnished with shellac varnish containing the aluminum or other metallic powder in a state of suspension, the shellac varnish constituting a convenient vehicle whereby the aluminum or other metallic powder may be applied in an even coating'to the composition or the like. 4

For percussion ca s containing from 0.03 .to 0.04 gram of to minate composition we have found one drop of varnish having a specific gravity of from 0.84. to 0.86 and con-.

tamingten per centum of aluminum-powder in suspension for each cap to answer well.

For larger caps and detonators two or three drops of the above-varnish will generally be found sufficient; but the surface of the explosive should be completely'covered with the aluminum-"powder. when the varnish is dry. The 'quantity' of aluminum-powder added to the varnish may be varied within wide limits; but in all cases sufiicient oxidizmg agent- -such, for example, as potasslum ohloratemu'st be contained in the fulminate or sensitive composition in excess of that required by the composition itself for the completev combustion of the aluminumpowder covering. When the varnish in the cap or detonator is quite dry, it may be finally pressed, so as thereby to obtain a perfectly smooth fast-adhering coating of aluminum or other metallic powder on the surface Of the composition in the cap or detonator.

In applying the said invention to igniters,

fuses, or other primers containing a non-sensitive explosivesuch, for example, as gunpowder or any of the numerous guncotton nitroglycerin explosives the metallic powder may be applied as is hereinbefore described with respect to its application to er cussion-caps or detonators containing in nate or the like, or the said aluminum or other metallicpowder maybe intimately mixed with the nonsensitive explosive composition before it is introduced into the igniters, fuses, or the like, or the ex losive su stance may' be moistened wit a strong shellac varnish-Or other adhesive substance and the aluminum or other metallic powder be dusted thereon. Where the explosive composition does not-contain an excess of an .oxidizin agent, sufficient potassium chlorate or the 11 e is mixed with the alu'minum -or other metallic powder toin'sure its complete combustionion the ignition of the explosive substance.

Where the aluminum or other metallic powder is dusted onto shellac varnish or other adhesive with which the composition in the igniters, fuses, or the like is. moistened, i

the said varnish or adhesive, while firmly attaching'the metallic powder to the explosive composition, serves to protect the metallic powder from the composition. The addition of shellac varnish has the advantage of retarding the rate ofcombustion of the explo sive substance, while the aluminum or other metallic GOIIlbliStlOll, the combined effect-namely,

prolonged increased temperaturerendering good ignition absolutely certain.

In the case of igniters, fuses, or other prnners the non-sensitlvp explosive may be powder msur'es an increased heat on replaced by an inert substance,such as corkpowder, sawdust, or the like. 'Ihe corkpowder or the like is thoroughly moistened with a strong shellac varnish or other adhesive, and aluminum or other metallic powder mixed with the requisite quantity of potas- $111111 chlorate to insure complete combustion is mixed with the cork-powder or the like. When dry, an extremely light granular nonsensitive semi-explosive substance is obtained. The rapidity of combustion and the heat liberated on ignition may be varied by varying the proportion of the mixture of metallic powder and chlorate of potash to the corkpowder and also by employing cork-powder of various-sized grains.

A material prepared as follows is suited to small rimers and igniters: Of cork-powder, passe through a thirty but retained bya ninety mesh sieve, about eight grams are taken and thoroughly ground up wlth a thick shellac varnishuntil all the surface of the cork grams is covered with the varnish.

While damp, with the varnish 35.2 grams of a mixture of aluminum powder and potassium chlorate in fine powder is added and the whole thoroughly ground up together. The mixture of aluminum-powder and potassium chlorate is composed ofabout ten parts, by weight, of the former to twenty-four parts, by weight, of the latter. When dry, thesubstance is sieved by means of a thirty-mesh sieve, and the material passing therethrough is again sieved by means of a ninety-mesh sieve, and the material retained by the said ninety-mesh sieve is found to be of suitable size. The cork in the substance acts as a buffer and renders the substance non-sensi- Although we prefer to apply the aluminum or other lllOtfilllC powder in one of the ways hereinbefore described, we wish it to be understood that it may be otherwise applied. For (Xample, the prepared varnish may be evenly coated or spread on one or both sides 01 sheets of paper and allowed to dry. Where one side only of the sheets of paper is coated with the prepared or metallic varnish,

the other side is coated with plain or nontain, but the explosion of percussion-caps en masse is rendered practically impossible and a regularity in the ballistics of smallarm cartridges using modified cordite as a proptllant results unattainable by the use of ordinary percussion-caps.

Having now described our invention, what we claim as new, and desire to secure by Letters Patent, is-

1. An explosive substance containing an excess of an oxidizing agent and coated with a varnish having suspended therein a pow: deredcombustible metal.

2. An explosive substance containing an excess of an oxidizing agent and coated with a varnish having suspended therein powtive to shock, while the potassium chlorate, l dered aluminium.

being fixed and waterproofed by the shellac i varnish, does not eflioresce on repeated moistening and drying.

For the purpose of rendering the cork more combustible it may be boiled in a strong solution of potassium chlorate and dried before being treated with the shellac and aluminum and chlorate mixture.

In testimony whereof we have hereunto set our hands in presence of two subscribing witnesses.

THOMAS ABRAHAM BAYLISS. HENRY WINDER BROWNSDON. Witnesses: A

, ERNEST HARKER,

MARSHAL HALSTEAD. 

